Self-sealing asphalt shingle and process for making same



May 3, 1960 A. DUNBAR ET AL SELF-SEALING ASPHALT SHINGLE AND PROCESS FOR MAKING SAME Filed June 10, 1957 FROM 1- 0; 5/1/0161 E FHONT OFSH/NGLE FRONT OF SH/NGL E INVENTORS. A'luerfllmbfir, 'alyeJflallsimm z Ward ,5. 10/7/7501? fly 624/; W

' ATTORNEYS m r J United States Patent F 2,935,416 7 SELF-SEALING ASPHALT SHINGLE AND PROCESS FOR MAKING SAME Alver Dunbar, Philadelphia, Pa., George J. Hausmann, Merehantville, N.J., and Bayard S. Johnson, Ardmore, Pa., assignors to Franklin Research Company, Philadelphia, Pa., a corporation of Pennsylvania Application June 10, 1957, Serial No, 664,769 11 Claims. (Cl. 117-4) In order to reduce or eliminate the tendency of the,

butt ends of flexible asphalt shingles to be lifted under the action of high winds, it has been proposed to provide a positive adherence across the butt end surfaces.

One Way which has been proposed for accomplishing this is to provide a coating on the back surface of the butts which becomes adhesive at temperatures encountered on a roof during the roofing season. Shingles provided with such a heat sensitive coating have proven to be quite satisfac tory once they are applied to a roof, but the prior art 1 2,935,416 1C6 Patented May 3, 1960 adhesive qualities at temperatures of the order of 125 F. and above, but of course the actual melting point of the asphalt may be somewhat higher. By way of example, a satisfactory heat sensitive asphalt is commercially avail- 6 able having the following general specifications:

has encountered great diificulties in storing and shipping such singles due to the fact that the adhesive coating is not only heat sensitive but is also pressure sensitive,

and therefore the shingles tend to stick to each other when they are stacked in bundles for storage and shipment.

The principal object of the present invention is to-provide a flexible asphalt shingle and a process for making' the same which will be self-sealing and at the same time be substantially non-adherent to adjoining shingles when the shingles are stacked for storage or shipment.

. A further object of the presentinvention is to provide a flexible asphalt shingle and a process for making the same in which heat sensitive strips will be provided on one surface and an anti-adhesive metallic oxide or metallic hydroxide film will be provided on the back surface and underlying the heat sensitive strips.

Further objects and advantages of the invention will become apparent from the detailed description which follows and from the accompanying drawings in which:

Fig. 1 is a plan view in diagrammatic form and partly broken away of a web and coating and cutting means for the formation of shingles;

Fig. 2 is an enlarged perspective view of a single flexible shingle of the present invention;

Fig. 3 is an enlarged view in perspectiveshowing a stack of the shingles of the present invention;

Fig. 4 is a cross-sectional view taken along the line IVIV of Fig. 3; and

Fig. 5 is a plan view of a roof portion to which a numberof the shingles of the present invention have been affixed.

'In the drawings the process steps for producing the non-adherent shingle of the present invention are best shown in Fig. 1 wherein a relatively hot flexible asphalt web 10 is provided with a series of heat sensitive strips 11 by means of a roller 12 having interrupted raised portions 13 to which is fed a relatively low melting point asphalt. p

The basic sheet or web may be prepared in the'usual way well known in the art and is'customarily made up of a fibrous felt base which has been saturated with asphalt and which may be provided with a mineral surfacing on the front surface. The asphalt used in forming the strips 11 should have a heat sensitivity such that it exhibits Viscosity Saybolt at 300 F 300-330; Viscosity Saybolt at 350 F Below the web 10 there is positioned a roll 14 having raised portions 15 which are fed from below with a special anti-adhesive composition of the type hereinafter described in detail. The action of the roll 14 and the raised portion 15 is to deposit a thin film 16 on the back of the hot web 10 beneath the heat sensitive strips 11 as shown by the dotted lines in Fig. 1. The thin film thus deposited'is very quickly dried'by the heat of web 10 forming an adherent coating corresponding to the strip 16 as shown in Fig. 2. Roll 17 is provided with cutting elements 18 and 19, thus providing individual shingles as shown at 20. As the individual shingles 20 come off the end of the machine they are collected in stacks, one of which is shown in perspective in Fig. 3, and in section in Fig. 4. As each shingle is deposited on the top or front surface of the preceding shingle the anti-adhesive strip 16 which extends across the back of each shingle entirely overlaps the heat sensitive strips 11 and therefore the only surfacemaking contact with the heat sensitive strips so long as the shingles remain in the stack is the surface of the dried strip 16 comprising the anti-adhesive material.

In the practice of the present invention, the composi-- tion of the anti-adhesive material used in forming the strip 16 is impo'rtant, and therefore preferred examples of suitable anti-adhesive compositions for use in the prac-- tice of the present invention are set forth below.

B. Metallic salt:

Basic aluminum acetate, Al(C H O OH 186 The basic aluminum acetate of B was dissolved in a part of the Water content listed for the wax emulsion A and then added with stirring to the wax emulsion of A.

Example 2 Zinc acetate, zirconium acetate, barium acetate and calcium acetate, respectively, were used in place of the basic aluminum acetate of Example 1, in each case in the amount of 186 parts by weight dissolved in a portion of the water content listed for the wax emulsion A of Example 1.

Example 3 I A. Wax emulsion: Parts by wt. Refined paraflin 600 Starch 50 Alrosperse llP (fatty amine condensate) (Alrose Chemical Co.) 12

Neutronyx 600 active aromatic poly- V glycol ether) (Onyx Oil & Chemical Co.) 12

Atlas G-3920 (Polyoxyethylene oleyl ether) 12 f Water 2720 B. Metallic saltz;

Basic aluminum acetate, Al(C H O OH 372- V 3 Example 4 A. Wax emulsion: Parts by wt. Refined parafiin 180 Oxidized microcrystalline paraffin (Crown 36) 20 Emulsifier 40 Water 720 B. Metallic salt:

Basic aluminum acetate, Al(C H O OH 240 One part by weight-of the metallic salt of B dissolved in a small portion of the waterof- A was mixed with 4 partsby weight of the wax emulsion of A. The emulsifier for the refined paraflin was non-ionic consisting of a mixturein equal'parts ofpolyoxyethylene oleyl ether (Atlas G.3920) and the monostearate of sorbitan (Span 60).

Both products are made and soldby Atlas Powder Co. of .Wilmington, Delaware.

B. Metallic salt:

Basic-aluminum acetate,

Al(C H O OH 28% solution.

One part by weight of a 28% solution of basic aluminum acetate is mixed with four parts by weight of the wax emulsion of A although it should be noted that aluminum acetate solution is miscible with the emulsion of A in all proportions. The resulting composition provides a film which dries with a gloss which is advantageous under certain conditions of use.

The composition of the anti-adhesive material-used in the practice of the present invention-consists broadly of a liquid containing a water soluble waxy material or an emulsified water insoluble waxy material and a compo nent which on drying will form a water resistant film containing a metallic salt of an acid selected from the group consisting of hydrochloric acid, hydrobromic acid, formic acid and acetic acid, with the metal being selected from the group consisting of aluminum, zinc and zirconium. It is believed that the waxy film and metallic salt thus deposited form in the pores and on the surface of the coated material either the hydroxide or the oxide of the metal salt. We have discovered that sucna waxy coatinghas the peculiar and unexpected property of resisting the normal adhesion which occurswhcn a relatively low temperature adhesive asphalt comesv into contact with another surface. We have further found that the anti-sticking effect is obtained with such metal oxide waxy films on application of the film to the smooth undersurface of an asphalt type web 'such as employed in making flexible asphalt shingles. The relatively smooth back surface of the web is particularly suitable for the application of the liquid anti-adhesive composition, and the fact that the web is'heated provides'a degree of porosity and a relatively quick drying effect which results in the deposit of water resistant metallic oxides or hydroxides in the form of a substantially continuous film which has the surprising characteristic of resisting adhesion to the relatively low melting point asphalt comprising strips 11 even on prolonged periods of storage and during shipment even in the summer months where temperatures may be of the order of'100 F. At the same time, the anti-adhesive film 16 is sufiiciently adherent to the back surface of the shingle so as to resist transfer in any substantial amount to the adhesive strip 11, and consequently the untreated back surface of the shingle along the butt surfaces is adhesively held. to the strips .4 11 when the shingles are laid on the roof as shown in Fig. 5. This adhesive action would of course be very much reduced in the event that there was any substantial transfer of the non-adhesive film to the strips 11 and any such interference must be avoided since it would defeat the primary purpose of a self-sealing shingle.

In the above examples it should be noted that carnauba Wax, sugar cane Wax, or equivalent synthetic waxes maybe used in conjunction With the refined paraffin or in place thereof.

Having thus described our invention, we claim:

1. A flexiblezshingle ofv the asphalt composition type having on its front surface a relatively narrow band of an asphalt layer extending in a lengthwise direction of the-shingleand-positioned substantially along a lengthwise medial line thereof, said asphalt layer being characterized by the factthat' its adhesive properties are energized attemperatures -of the order of F. and

having on its back surface an anti-adhesive coating underlying said. asphalt band, said anti-adhesive coatingcomprising a water resistant film containing a waxy material and a metallic salt of an acid selected from the group consisting of hydrochloric acid, hydrobromic acid,

formic acid and acetic acid, the metal of said salt being' selected from the group consisting of aluminum, zinc andzirconium.

2. The flexible shingle of claim 1 further character-- ized by the fact that the waxy material consists of paraffin wax.

3. The flexible shingle of claim 1 further characterized by the fact that the waxy material consists of a-mix-- tureof parafiin wax and a hard wax.

4.. The flexible shingle of claim 1 further characterized by the fact that the metallic salt consists of a metallic acetate selected from the group consisting of aluminum acetate, zinc acetate and zirconium acetate.

5. The flexible shingle of claim 1 further characterized by the fact that the metallic salt consists of aluminum acetate.

6. The flexible shingle of claim 1 further characterized by the fact that the metallic salt consists of Zinc acetate.

7. The flexible shingle of claim 1 further characterized by the fact that the metallic salt consists of zirconium acetate.

8. The process of producing a flexible shingle of the asphalt composition type comprising the steps of applying relatively narrow bands of asphalt material characterized by the fact that its adhesive properties are energized at temperatures, of the order of 125 F. on the front surface of an asphalt impregnated sheet and depositing on the. reverse side of said asphalt impregnated sheet and underlying said asphalt bands a liquid film consisting of' an aqueous solution of a metallic salt of an acid selected from the group consisting of-hydrochloric acid, hydrobromic acid, formic acidand acetic acid, with the metal being selected from the group consisting of aluminum, zinc and zirconium, in combination with a binder comprising a waxy material, and then drying said liquid film to deposit an adherent coating substantially non-adhesive to the asphalt material forming said narrow bands.

9. The process of claim 8 in which the aqueous film consists of a metallic acetate selected from the group;

alongthe medial line thereof and inwardly of the, said:

cutout portions, said asphalt layer being characterized by the fact that its adhesive properties are energized at temperatures of the order of 125 F. and having on its back surface an anti-adhesive coating underlying said asphalt band, said anti-adhesive coating comprising a water resistant film containing a waxy material and a metallic salt of an acid selected from the group consisting of hydrochloric acid, hydrobromic acid, formic acid References Cited in the file of this patent UNITED STATES PATENTS Kirschbraun Aug. 6, 1940 Kirschbraun June 10, 1947 UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECTION Patent No. 2,935.416 May 3, 1960 I Alver Dunbar et al0 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 29, for "singles" read shingles Signed and sealed this 27th day of September 1960.

(SEAL)-: Attest:

KARL H. AXLINE ROBERT (1. WATSON Attesting Officer Commissioner of Patents 

1. A FLEXIBLE SHINGLE OF THE ASHPHALT COMPOSITION TYPE HAVING ON ITS FRONT SURFACE A RELATIVELY NARROW BAND OF AN ASPHALT LAYER EXTENDING IN A LENGTHWISE DIRECTION OF THE SHINGLE AND POSITIONED SUBSTANTIALLY ALONG A LENGTHWISE MEDIAL LINE THEREOF, SAID ASPHALT LAYER BEING CHARACTERIZED BY THE FACT THAT ITS ADHESIVE PROPERTIES ARE ENERGIZED AT TEMPERATURES OF THE ORDER OF 125*F. AND HAVING ON ITS BACK SURFACE, AN ANTI-ADHESIVE COATING UNDERLYING SAID ASPHALT BAND, SAID ANTI-ADHESIVE COATING COMPRISING A WATER RESISTANT FILM CONTAINING A WAXY MATERIAL AND A METALLIC SALT OF AN ACID SELECTED FROM THE GROUP CONSISTING OF HYDROCHLORIC ACID, HYDROBROMIC ACID, FORMIC ACID AND ACETIC ACID, THE METAL OF SAID SALT BEING SELECTED FROM THE GROUP CONSISTING OF ALUMINUM, ZINC AND ZIRCONUIM. 